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You need to close the top screws and watch peak RPM. If RPM is still rising when the screws bottom ,install a smaller main jet, open the screws and repeat until max RPM is found. I have a 62t 701 with a stock 760 intake. It has 140 mains with the screws open around 1/2 turn out. I would expect...

What number is on the plug? If they are NGK #6 then it would be very rich in order to make them that dark. If #9 it would be lean in order to make them that clean. My experience says use #8 and power tune the top screws, then adjust the pilot for good response. Generally it needs to be...

It would take a lot of ski owners with dynos before any published information could be trusted. I have PWC magazine adds that show a FPP 701 pipe claiming 12hp one month and 19hp the next. Everything has already been developed. As I have said before, pwc owners do not stick around long enough...

Higher pop off will make the pilot leaner. You could either install a lighter spring or larger pilot jets. Make sure to set the bottom screw well rich of peak idle rpm.

Kawasaki did this with their big pin manifolds and carbs, especially the Keihins. Basically they made the inlet tract area no larger than the throttle plate so only the Venturi is smaller. If it was practical we would mount the carb directly on top of the reeds. Our manifolds reduce signal...

It requires a certain scale of production in order to make anything price efficient. There is only enough world wide demand to keep one small factory running. I know airplanes and boats have suffered the same fate with too many suppliers. It ultimately makes prices much higher.

Thats a dangerous prediction. Much safer to make the main/top screw rich of peak rpm and the pilot just rich enough for good response. I have a 701 that needed 140 mains and a 750 that is still too rich with 115s. Both have SBN44s. I tried to explain to the engine what it needed, it ignored me.

Anyone ever try welding a 800/1200 reed inlet onto a 62T case? It may be worthwhile considering they were designed to feed a 400cc cylinder at similar rpms. Our 62T case comes up short when compared to other similarly sized engines, even outboards. I think PWC consumers are easy targets for...

Buy a Mikuni carb kit and replace and/or clean the parts individually. I have never needed anything stronger than carb spray. If I did then the whole engine was rusted as well.

They need to add a lot of water to counteract their noisy waterbox.

Pull the plug caps, trim back the insulation, and pull on the center wire. It’s probably okay if the wire won’t pull out. Next look at the stator, they are likely to cause temperature related problems.

Our pipes will make the mixture go rich when RPM is out of its resonate range. That’s why a bigger carb doesn’t go any faster. They do improve acceleration though. As a group our problem is so many choices and so little experience, riders come and go with the wind. FWIW, SBN44s work well on...

The outboard guys are using EFI and a sliding plate over the reed block that completely uncovers the entire area. It has already been developed and is not difficult to tune. It is actually much easier to tune with outboards since they have no tuned pipe to compensate for. I think someone in...

My sizing standards are easy. It needs to hit the pipe no later than 50% open. If the pipe hits below 40% the carb is too big. If the jetting becomes sensitive, the carb is too big. If I have to lower popoff and jack with the pump pressure, the carb is way too big!!!! I might as well make a...

I have to be awfully desperate before I run a boring bar down the throat of a standard SBN46.

In the jetski world, properly sized is whatever carb has the largest number attached to its name.

An ADA head has no gasket to control water flow so you need a little more water going through the cylinder. That’s their only disadvantage.

A single pipe triple has very little pipe tuning effect. They need to run higher combustion temps to make full power. Thats why you cant push the compression very high. Twin cylinder with a good pipe will go rich at peak rpm if the pump load is set correctly. Thats why they are much more likely...

If you have the case disassembled its easy to add another pulse fitting on the other cylinder. The case already has a pad for it and you can plug it when not in use. The single pump works fine with 38s. I use a single remote pump and block-off plates to replace the carb pumps. .All my friends...

I have a 701 Jammer with a 144 pump. It can crab nearly completely sideways. It doesnt drift like something with wheels because it steers from the rear. Its more like add more turn get more sideways.